常开or常关? 楼主,没错 还有几个pid阀位常见的缩写: fc ( air and electrical fail close ) 空气和电事故关 fo( air and electrical fail open) 空气和电事故开 fl(fail last position )保持故障位置(阀位不变) efc(electrical failed close )电事故关 efo(electrical failed open )电事故开 afl(air fail last position )空气故障保持原位置(阀位不变) nnf (normally no flow) 正常无流量 hpt(high point )高点 lpt(low point )低点查看更多